The IS12T is no slouch of a phone: It’s near waterproof, has a 13 megapixel camera, and runs Mango on its 32 gigabytes of storage. In other words, it’s probably the most capable Windows Phone 7 handset (about to be) in the market.

And its price matches its specifications. Now, admittedly the Dollar has had a horrible year against the Yen, so the following conversions might be a touch exaggerated, but check them out all the same:

IS12T New retail price $958

IS12T MNP retail price $753

IS12T New price with 2-year contract $458

IS12T MNP price with 2-year contract $252

(USD/JPY = 76.715) (MNP price is for NTT docomo and Softbank users who want to switch to KDDI)

In other words, the MNP prices are only for people who switch carriers. The subsidized price of the phone, for people already on KDDI, is over $450. That feels, as we said, too high.

But if you factor in the slide of the US currency, and the technological prowess of the IS12T, and its neat new keyboard, it could be a modest success. But that in mind, our gut reaction is that a cheaper, perhaps slightly less capable phone, would have been a better match for the Japanese market, a place that Windows Phone has yet to touch.

Even though the IS12T is a very interesting phone, its high cost could keep curious people away from WP7 in the country. Of course, cheaper handsets could follow, but for now, this is the only WP7 handset heading to the Japanese market.